Pre-production trials at the Merlin Diamond Project in Australia's Northern Territory were successful, recovering 10,600 carats of diamonds, North Australian Diamonds Ltd (NADL) reports.

Over 24% of the diamonds yielded by the Merlin project during the trials were 1 carat or larger. Of these, 75% were found to be gem-quality or near gem-quality stones. The largest diamond recovered during the trials was a gem-quality stone weighing 24.12 carats.

New methodologies tested by the diamond company during this period improved diamond recovery by 20% - putting the grade for the project's Gawain pipe at 41 carats per hundred tons of ore. Drilling at the Merlin project in the first half of 2010 indicated diamond resources of some 7.1 million carats.

NADL was running the pre-production trials at Merlin with a number of goals: to test new technology; to optimize the diamond recovery process in hope of reducing the eventual labor force required; to confirm the grades of recoverable diamonds and assess size distribution; and to assemble a parcel of diamonds for valuation and marketing.